From patchwork Wed Jun 21 12:50:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 9801791 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 981FB6038C for ; Wed, 21 Jun 2017 13:08:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 83FBA2074F for ; Wed, 21 Jun 2017 13:08:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7609A2856F; Wed, 21 Jun 2017 13:08:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DD9242074F for ; Wed, 21 Jun 2017 13:08:51 +0000 (UTC) Received: from localhost ([::1]:53842 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dNfNK-0006gM-DX for patchwork-qemu-devel@patchwork.kernel.org; Wed, 21 Jun 2017 09:08:50 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34513) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dNf7C-0008Ub-9c for qemu-devel@nongnu.org; Wed, 21 Jun 2017 08:52:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dNf7B-0005YX-CJ for qemu-devel@nongnu.org; Wed, 21 Jun 2017 08:52:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58062) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dNf78-0005X6-D8; Wed, 21 Jun 2017 08:52:06 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5FEA37CE12; Wed, 21 Jun 2017 12:52:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5FEA37CE12 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mreitz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 5FEA37CE12 Received: from localhost (unknown [10.40.205.46]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B51D4702C0; Wed, 21 Jun 2017 12:52:04 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 21 Jun 2017 14:50:45 +0200 Message-Id: <20170621125047.30294-24-mreitz@redhat.com> In-Reply-To: <20170621125047.30294-1-mreitz@redhat.com> References: <20170621125047.30294-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 21 Jun 2017 12:52:05 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v5 23/25] block: Fix FIXME from "Add BDS.backing_overridden" X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Alberto Garcia , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Said commit introduced a FIXME stating that bdrv_open_backing_file() should set bs->backing_overridden to true not only if the file.filename option was set, but if the "options" QDict contained any option that is significant for any node in the BDS tree emerging from the backing BDS. This behavior is implemented by this patch. Signed-off-by: Max Reitz --- block.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 75 insertions(+), 6 deletions(-) diff --git a/block.c b/block.c index 2542ff5..2c3c983 100644 --- a/block.c +++ b/block.c @@ -74,6 +74,9 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, const BdrvChildRole *child_role, Error **errp); +static bool has_significant_runtime_options(BlockDriverState *bs, + const QDict *d); + /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; @@ -2124,6 +2127,42 @@ out: bdrv_refresh_limits(bs, NULL); } +/** + * Checks whether @options contains any significant option for any of the nodes + * in the BDS tree emerging from @bs. + */ +static bool is_significant_option_tree(BlockDriverState *bs, QDict *options) +{ + BdrvChild *child; + + if (!qdict_size(options)) { + /* No need to recurse */ + return false; + } + + if (has_significant_runtime_options(bs, options)) { + return true; + } + + QLIST_FOREACH(child, &bs->children, next) { + QDict *child_options; + char *option_prefix; + + option_prefix = g_strdup_printf("%s.", child->name); + qdict_extract_subqdict(options, &child_options, option_prefix); + g_free(option_prefix); + + if (is_significant_option_tree(child->bs, child_options)) { + QDECREF(child_options); + return true; + } + + QDECREF(child_options); + } + + return false; +} + /* * Opens the backing file for a BlockDriverState if not yet open * @@ -2142,7 +2181,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *reference = NULL; int ret = 0; BlockDriverState *backing_hd; - QDict *options; + QDict *options, *cloned_options = NULL; QDict *tmp_parent_options = NULL; Error *local_err = NULL; @@ -2172,11 +2211,6 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, reference = qdict_get_try_str(parent_options, bdref_key); if (reference || qdict_haskey(options, "file.filename")) { /* keep backing_filename NULL */ - - /* FIXME: Should also be set to true if @options contains other runtime - * options which control the data that is read from the backing - * BDS */ - bs->backing_overridden = true; } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { QDECREF(options); goto free_exit; @@ -2197,6 +2231,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } + cloned_options = qdict_clone_shallow(options); + if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { qdict_put_str(options, "driver", bs->backing_format); } @@ -2210,6 +2246,10 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } + if (reference || is_significant_option_tree(backing_hd, cloned_options)) { + bs->backing_overridden = true; + } + /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ bdrv_set_backing_hd(bs, backing_hd, &local_err); @@ -2225,6 +2265,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, free_exit: g_free(backing_filename); QDECREF(tmp_parent_options); + QDECREF(cloned_options); return ret; } @@ -4802,6 +4843,34 @@ static const char *const *significant_options(BlockDriverState *bs, } /** + * Returns true if @d contains any options the block driver of @bs considers to + * be significant runtime options. + */ +static bool has_significant_runtime_options(BlockDriverState *bs, + const QDict *d) +{ + const char *const *option_name = NULL; + + while ((option_name = significant_options(bs, option_name))) { + assert(strlen(*option_name) > 0); + if ((*option_name)[strlen(*option_name) - 1] != '.') { + if (qdict_haskey(d, *option_name)) { + return true; + } + } else { + const QDictEntry *entry; + for (entry = qdict_first(d); entry; entry = qdict_next(d, entry)) { + if (strstart(qdict_entry_key(entry), *option_name, NULL)) { + return true; + } + } + } + } + + return false; +} + +/** * Copies all significant runtime options from bs->options to the given QDict. * The set of significant option keys is determined by invoking * significant_options().